Subversion Repositories filter_foundry

%{

/*
    This file is part of "Filter Foundry", a filter plugin for Adobe Photoshop
    Copyright (C) 2003-2009 Toby Thain, toby@telegraphics.com.au
    Copyright (C) 2018-2019 Daniel Marschall, ViaThinkSoft

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by  
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License  
    along with this program; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/

#include <stdio.h>
#include <string.h>

#ifndef false
#define false 0
#define true 1
#endif

#include "node.h"
#include "y.tab.h"

//#ifdef MAC_ENV
int yyparse(void);
int yylex(void); // hack. correct prototype is buried in lex output
//#endif
void yyerror(char*);
int pushflag(int x);
struct node *parseexpr(char *s);

#define DPARSE 

struct node *parsetree;
char *errstr;

enum{ PARENSTACK = 100 };

int inarglist[PARENSTACK],arglistptr; // keep track of whether a comma is an function argument separator, or operator

int pushflag(int x){
        if(arglistptr < (PARENSTACK-1))
                inarglist[++arglistptr] = x;
        else{
                yyerror(_strdup("too many nested parentheses or function calls"));
                return true;
        }
        return false;
}

#define POP() --arglistptr

#define ENTERARGS() if(pushflag(true)) YYERROR
#define ENTERPAREN() if(pushflag(false)) YYERROR
#define LEAVEARGS POP
#define LEAVEPAREN POP

%}

%token TOK_NUM TOK_EOF TOK_ARGSEP
%token TOK_FN1 TOK_FN2 TOK_FN3 TOK_FN4 TOK_FN5 TOK_FN10
%token TOK_SPECIALVAR TOK_VAR TOK_UNKNOWN TOK_BADCHAR

%left ','
%right '?' ':'
%left LOGAND LOGOR
%left '&' '^' '|'
%left EQ NE
%left '<' LE '>' GE
%left SHLEFT SHRIGHT
%left '-' '+'
%left '*' '/' '%'
%right EXP
%left NEG 

%%

input : expr { parsetree = $1; } ;

expr : TOK_NUM 
        | TOK_VAR
        | TOK_SPECIALVAR
        | TOK_FN1 '(' {ENTERARGS();} expr ')' {LEAVEARGS();}
                { $$ = $1; $$->child[0] = $4; }
        | TOK_FN2 '(' {ENTERARGS();} expr TOK_ARGSEP expr ')' {LEAVEARGS();}
                { $$ = $1; $$->child[0] = $4; $$->child[1] = $6; }
        | TOK_FN3 '(' {ENTERARGS();} expr TOK_ARGSEP expr TOK_ARGSEP expr ')' {LEAVEARGS();}
                { $$ = $1; $$->child[0] = $4; $$->child[1] = $6; $$->child[2] = $8; }
        | TOK_FN4 '(' {ENTERARGS();} expr TOK_ARGSEP expr TOK_ARGSEP expr TOK_ARGSEP expr ')' {LEAVEARGS();}
                { $$ = $1; $$->child[0] = $4; $$->child[1] = $6; $$->child[2] = $8; $$->child[3] = $10; }
        | TOK_FN5 '(' {ENTERARGS();} expr TOK_ARGSEP expr TOK_ARGSEP expr TOK_ARGSEP expr TOK_ARGSEP expr ')' {LEAVEARGS();}
                { $$ = $1; $$->child[0] = $4; $$->child[1] = $6; $$->child[2] = $8; $$->child[3] = $10; $$->child[4] = $12; }
        | TOK_FN10 '(' {ENTERARGS();} 
                        expr TOK_ARGSEP expr TOK_ARGSEP expr TOK_ARGSEP expr TOK_ARGSEP expr TOK_ARGSEP
                        expr TOK_ARGSEP expr TOK_ARGSEP expr TOK_ARGSEP expr TOK_ARGSEP expr
                        ')' {LEAVEARGS();}
                { $$ = $1; 
                        $$->child[0] = $4;  $$->child[1] = $6;  $$->child[2] = $8;  $$->child[3] = $10; $$->child[4] = $12;
                        $$->child[5] = $14; $$->child[6] = $16; $$->child[7] = $18; $$->child[8] = $20; $$->child[9] = $22; 
                }
        | '(' {ENTERPAREN();} expr ')' { LEAVEPAREN(); $$ = $3; }
/* arithmetic operators */
        | expr '+' expr { $$ = $2; $$->child[0] = $1; $$->child[1] = $3; }
        | expr '-' expr { $$ = $2; $$->child[0] = $1; $$->child[1] = $3; }
        | expr '*' expr { $$ = $2; $$->child[0] = $1; $$->child[1] = $3; }
        | expr '/' expr { $$ = $2; $$->child[0] = $1; $$->child[1] = $3; }
        | expr '%' expr { $$ = $2; $$->child[0] = $1; $$->child[1] = $3; }
/* exponentiation (not in FF spec) */
        | expr EXP expr { $$ = $2; $$->child[0] = $1; $$->child[1] = $3; }
/* relational operators */
        | expr EQ expr  { $$ = $2; $$->child[0] = $1; $$->child[1] = $3; }
        | expr NE expr  { $$ = $2; $$->child[0] = $1; $$->child[1] = $3; }
        | expr '<' expr { $$ = $2; $$->child[0] = $1; $$->child[1] = $3; }
        | expr LE expr  { $$ = $2; $$->child[0] = $1; $$->child[1] = $3; }
        | expr '>' expr { $$ = $2; $$->child[0] = $1; $$->child[1] = $3; }
        | expr GE expr  { $$ = $2; $$->child[0] = $1; $$->child[1] = $3; }
/* logical operators */
        | expr LOGAND expr { $$ = $2; $$->child[0] = $1; $$->child[1] = $3; }
        | expr LOGOR expr  { $$ = $2; $$->child[0] = $1; $$->child[1] = $3; }
        | '!' expr %prec NEG { $$ = $1; $$->child[0] = $2; }
/* conditional operator */
        | expr '?' expr ':' expr
                { $$ = $2; $$->child[0] = $1; $$->child[1] = $3; $$->child[2] = $5; }
/* bitwise operators */
        | expr '&' expr { $$ = $2; $$->child[0] = $1; $$->child[1] = $3; }
        | expr '^' expr { $$ = $2; $$->child[0] = $1; $$->child[1] = $3; }
        | expr '|' expr { $$ = $2; $$->child[0] = $1; $$->child[1] = $3; }
        | expr SHLEFT expr  { $$ = $2; $$->child[0] = $1; $$->child[1] = $3; }
        | expr SHRIGHT expr { $$ = $2; $$->child[0] = $1; $$->child[1] = $3; }
        | '~' expr %prec NEG { $$ = $1; $$->child[0] = $2; }
/* sequence operator */
        | expr ',' expr { $$ = $2; $$->child[0] = $1; $$->child[1] = $3; }
/* unary operators */
        | '-' expr %prec NEG { $$ = $1; $$->child[0] = 0; $$->child[1] = $2; }
        | '+' expr %prec NEG { $$ = $2; }
/* error tokens */
        | TOK_UNKNOWN { yyerror(_strdup("unknown name")); YYERROR; }
        | TOK_BADCHAR { yyerror(_strdup("disallowed character")); YYERROR; }
        ;

%%

// Daniel 06 July 2021: Move these two lines out of the function parseexpr(), otherwise the code won't compile in G++
struct yy_buffer_state *yy_scan_string(const char*); // hack. correct prototype is buried in lex output
int yyparse(void); // hack. correct prototype appears just after this code, in yacc output

struct node *parseexpr(char *s){
        extern int tokpos,tokstart;
        
        tokstart = tokpos = 0;

        if(s){
                arglistptr = 0;
                inarglist[arglistptr] = false;
        
                node_list = 0;
                yy_scan_string(s);
        
                if(!yyparse())
                        return parsetree;
                else /* ensure we don't leak memory, on an unsuccessful parse */
                        freeallnodes();
        }else
                yyerror(_strdup("null string???"));
        return 0;
}

void yyerror(char *msg){
        errstr = msg;
}